Recording & Replay
HMCLS recordings capture the full acquisition stream to disk as a .hmcls file. Recordings can be replayed later at variable speed, letting you re-analyze data with different panel settings without reconnecting to hardware.
Starting a Recording
- Connect to a device and start acquisition.
- Click the Record button (⏺) in the app toolbar.
- Choose a save location — the app begins writing the acquisition stream continuously.
- Click Stop Recording (⏹) to finish. The file is finalized and ready for replay.
An existing recording is never overwritten: if the chosen name is already taken, the app saves the new file as name_1.hmcls, name_2.hmcls, and so on.
Recording captures raw acquisition data only. Studio program output (say/log) appears in the terminal during recording but is not stored in the file.
Loading a Recording for Replay
- Click Load Recording (📂) in the toolbar.
- Select a
.hmclsfile. - The app enters Replay Mode — the acquisition stream is replaced by the file contents.
- The UDP Commands panel switches to playback controls.
Playback Controls
The following controls appear in the UDP Commands panel when in replay mode:
| Control | Description |
|---|---|
| Play / Pause | Start or pause playback |
| Seek slider | Scrub to any position in the recording |
| Speed | 0.25×, 0.5×, 1×, 2×, 4× |
What Works in Replay Mode
| Feature | Status |
|---|---|
| Signal Viewer, Raster, Heatmap, STA | Fully functional |
| Serial Terminal | Shows "unavailable in replay" — no live commands can be sent |
| Studio programming | Not available (device not connected) |
Exiting Replay Mode
Click Disconnect or Connect to Device to return to live mode.
File Format
.hmcls files contain raw sample data with a header describing channel count, sample rate, and recording duration. The format is designed for sequential streaming; seeking loads data from the appropriate file offset.